The Transgenic Mouse/ES Cell Shared Resource has been in existence since 1993 and has received continuous funding from the NCI since the Vanderbilt-lngram Cancer Center (VICC) was awarded its first Cancer Center Support Grant in 1995. At the time of the last competitive renewal, this shared resource received an Outstanding rating. This resource provides gene targeting, DNA pronuclear microinjections, ES cell microinjections, assisted reproduction and both sperm and embryo cryopreservation services to members of the VICC. These services are essential for the generation, maintenance, and long-term storage of germline-altered mice. The resource continues to function in a multidisciplinary manner and has undergone several significant changes since the last competitive evaluation that have enabled it to continue to provide gene targeting and microinjection services at reasonable prices, to develop several new services, and to improve both its quality control and data management strategies. The Transgenic Mouse/ES Cell Shared Resource continues to offer services that remain in high demand and vital to the generation of new mouse models of cancer and other diseases. This will be critical as the gene-specific information from genome-wide cancer studies is translated to mouse models of human cancer. Moreover, the technology base that this resource supports is expected to be important in allowing Vanderbilt investigators to adapt to using of human pluripotent stem cells in the future.